Developing new CTA/CA-based membrane containing hydrophilic nanoparticles to enhance the forward osmosis desalination

Abstract Forward osmosis (FO) has developed as a new process with many potential applications in water production. The lack of an adequately designed membrane is the major challenge which hinders FO development. In this study, membrane science along with nanotechnology has been applied to build a high performance FO membrane. Boehmite nanoparticles, a hydrophilic additive containing extra hydroxyl groups on its surface, promoted cellulose acetate/cellulose triacetate (CA/CTA)-based membrane performance for FO applications. The characterization of the resultant nanocomposite membranes exhibited that the physiochemical properties, structural parameter and performance were improved. Loading 0.5 wt.% of the nanoparticles enhanced the water permeability about three times without a considerable increase in salt permeability and produced an excellent permselectivity compared with the neat membrane. Moreover, the nanoparticle loading improved porosity of the nanocomposite membrane and reduced its structural parameter (S) to 0.53 mm. Higher porosity and desirable hydrophilicity of the modified membrane exhibited a reduced impact of internal concentration polarization (ICP), which generally influenced the FO processes. The performance results indicated that the modified membrane showed a superior FO performance compared with the commercially available FO membranes.